Publications

Authors:

Cellini, Barbara; Bertoldi, Mariarita; Montioli, Riccardo; Laurents, Dv; Paiardini, A; Voltattorni, Carla

Title:

Dimerization and Folding Processes of Treponema denticola Cystalysin: The Role of Pyridoxal 5'-Phosphate

Year:

2006

Type of item:

Articolo in Rivista

Tipologia ANVUR:

Articolo su rivista

Language:

Inglese

Referee:

Sì

Name of journal:

Biochemistry

ISSN of journal:

0006-2960

N° Volume:

45

:

ACS Publications

Page numbers:

14140-14154

Keyword:

cystalysin; dimerization; protein folding

Short description of contents:

Cystalysin, the key virulence factor in the bacterium Treponema denticola responsible for periodontitis, is a homodimeric pyridoxal 5′-phosphate (PLP)-C-S lyase. The dimerization process and the urea-induced unfolding equilibrium of holocystalysin were compared with those of the apo form. The presence of PLP decreases ∼4 times the monomer-dimer equilibrium dissociation constant. By using a variety of spectroscopic and analytical procedures, we demonstrated a difference in their unfolding profiles. Upon the monomerization of apocystalysin, occurring between 1 and 2 M urea, a self-associated equilibrium intermediate with a very high β-sheet content is stabilized over the 2.5-4 M urea range, giving rise to a fully unfolded monomer at higher urea concentrations. On the other hand, highly destabilizing conditions, accompanied by the formation of a significant amount of insoluble aggregates, are required for PLP release and monomerization. Refolding studies, together with analysis of the dissociation/association process of cystalysin, shed light on how the protein concentration and the presence or absence of PLP under refolding conditions could affect the recovery of the active dimeric enzyme and the production of insoluble aggregates. When the protein is completely denatured, the best reactivation yield found was ∼50% and 25% for holo and apocystalysin, respectively. The dimerization and folding processes of cystalysin have been compared with those of another PLP C-S lyase, MalY from E. coli, and the possible relevance of their PLP binding mode in these processes has been discussed. © 2006 American Chemical Society.

Product ID:

36851

Handle IRIS:

11562/305409

Deposited On:

July 19, 2007

Last Modified:

November 15, 2022

Bibliographic citation:

Cellini, Barbara; Bertoldi, Mariarita; Montioli, Riccardo; Laurents, Dv; Paiardini, A; Voltattorni, Carla, Dimerization and Folding Processes of Treponema denticola Cystalysin: The Role of Pyridoxal 5'-Phosphate «Biochemistry» , vol. 45 , 2006 , pp. 14140-14154

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